RT Journal Article SR Electronic T1 Changing patterns of cigarette and ENDS transitions in the USA: a multistate transition analysis of youth and adults in the PATH Study in 2015–2017 vs 2017–2019 JF Tobacco Control JO Tob Control FD BMJ Publishing Group Ltd SP tc-2022-057905 DO 10.1136/tc-2022-057905 A1 Brouwer, Andrew F A1 Jeon, Jihyoun A1 Jimenez-Mendoza, Evelyn A1 Land, Stephanie R A1 Holford, Theodore R A1 Friedman, Abigail S A1 Tam, Jamie A1 Mistry, Ritesh A1 Levy, David T A1 Meza, Rafael YR 2023 UL http://tobaccocontrol.bmj.com/content/early/2023/03/28/tc-2022-057905.abstract AB Introduction It is unknown how recent changes in the tobacco product marketplace have impacted transitions in cigarette and electronic nicotine delivery system (ENDS) use.Methods A multistate transition model was applied to 24 242 adults and 12 067 youth in waves 2–4 (2015–2017) and 28 061 adults and 12 538 youth in waves 4 and 5 (2017–2019) of the Population Assessment of Tobacco and Health Study. Transition rates for initiation, cessation and product transitions were estimated in multivariable models, accounting for gender, age group, race/ethnicity and daily versus non-daily product use.Results Changes in ENDS initiation/relapse rates depended on age, including among adults. Among youth who had never established tobacco use, the 1-year probability of ENDS initiation increased after 2017 from 1.6% (95% CI 1.4% to 1.8%) to 3.8% (95% CI 3.4% to 4.2%). Persistence of ENDS-only use (ie, 1-year probability of continuing to use ENDS only) increased for youth from 40.7% (95% CI 34.4% to 46.9%) to 65.7% (95% CI 60.5% to 71.1%) and for adults from 57.8% (95% CI 54.4% to 61.3%) to 78.2% (95% CI 76.0% to 80.4%). Persistence of dual use similarly increased for youth from 48.3% (95% CI 37.4% to 59.2%) to 60.9% (95% CI 43.0% to 78.8%) and for adults from 40.1% (95% CI 37.0% to 43.2%) to 63.8% (95% CI 59.6% to 67.6%). Youth and young adults who used both products became more likely to transition to ENDS-only use, but middle-aged and older adults did not.Conclusions ENDS-only and dual use became more persistent. Middle-aged and older adults who used both products became less likely to transition to cigarette-only use but not more likely to discontinue cigarettes. Youth and young adults became more likely to transition to ENDS-only use.Most data are available in a public, open access repository. Other data may be obtained from a third party and are not publicly available. Public Use Files from the Population Assessment of Tobacco and Health Study are available for download from an open access repository (https://doi.org/10.3886/ICPSR36498.v17). Restricted-use files (https://doi.org/10.3886/ICPSR36231.v31) require a restricted data use agreement. Conditions of use are available on the aforementioned websites.